There is a high incidence of accidental water leakage in various water distribution systems which may go undetected, thus exacerbating an ever increasing impact on the environment caused by water leakage and frustrating water conservation efforts. For example, households and residential neighborhoods may suffer from leaks which may develop in areas which are not easily detectable, which may lead to potential mold growth, property damage, as well as large water bills. Water leaks from broken sprinkler system or a ruptured water pipe, for example, can lead to significant water loss in a relatively short period of time.
Known approaches for detecting water leaks involve a process of classifying water consumption of each fixture (e.g., faucet, shower, toilet, etc.) in a household to develop pressure change signatures associated with opening and closing the fixtures. For example, Patel et al., U.S. Pat. No. 8,457,908, entitled, “Sensing events affecting liquid flow in a liquid distribution system” (hereinafter, “Patel”) discloses monitoring pressure transients of fixtures based on their pre-identified signatures to detect whether there are deviations therefrom to suggest a water leak. However, Patel's approach may be best suitable in a controlled environment wherein interference from external factors such as external pressure fluctuation are artificially eliminated from affecting the water pressure of the fixtures in order to obtain the signatures; as such, these techniques may not be applicable to real time everyday settings where various external factors may affect the signatures of the fixtures. For example, water pressure fluctuation which may be introduced by changes in water consumption in a residential neighborhood can cause the pressure of the main water supply line to a household being monitored by Patel's system to drop; however such pressure drops from external factors may result in false positives of water leakage detection within the household because the water pressures of the various fixtures also correspondingly drop and deviate from their expected signatures. Typical pressure regulators prevent the incoming water pressure on the main supply line to a house from exceeding a particular set point, but do not prevent such water pressure drops in the neighborhood from being translated into a water pressure drop within individual households.
Furthermore, signature classification of fixtures is also frustrated in cases of compound fixtures comprising two or more component water fixtures because each component water fixture may have independent water consumption/usage characteristics which may not lend themselves to a well-defined signature for the compound fixtures. Moreover, the water consumption of some fixtures may be for a relatively small duration, e.g., washing one's hands at a sink can last for merely a few seconds, whereas taking a shower, running a dishwasher, or a washing machine, may last much longer. Thus, to account for even the small durations of usage, approaches such as Patel's may require very high sampling rates in (e.g., at a frequency of 1000 times per second or 1 KHz) to not overlook the events of short duration. As can be recognized, such high sampling rates come with high processing power consumption, which lends such approaches poorly to the use of mobile or handheld battery powered devices for monitoring the usage and potential deviations from established signatures for the fixtures.
Accordingly, there is a need in the art for reliable and effective water leakage detection techniques which avoid the aforementioned drawbacks of conventional approaches.